P0563 Code: System Voltage High
🟠 Moderate severity · drivable
Drivable in the short term, but high voltage can damage the battery and electronics, so check the charging system soon.
What P0563 means
The engine computer sees system voltage above about 16 volts. With the engine running, normal voltage is around 13.5–14.5 volts, so a high reading usually means the charging system is overcharging.
Symptoms
- Check engine light is on
- Battery or charging warning light
- Headlights too bright or flickering
- Battery swollen, hot, or leaking
- Electrical components failing
Common causes
- most common: Failing voltage regulator, often built into the alternator
- common: Faulty alternator
- common: Loose or corroded wiring and grounds
- less common: Faulty engine computer
How to fix it
| Fix | DIY? | Typical cost |
|---|---|---|
| Test the charging voltage with a multimeter | Yes | $0–20 |
| Clean and tighten the battery terminals and grounds | Yes | $0–20 |
| Replace the voltage regulator or alternator | Mechanic | $150–450 |
Frequently asked questions
Can I drive with a P0563 code?
Short trips, yes, but overcharging can damage the battery and electronics. Get the charging system checked soon.
What is the most common cause of P0563?
A failing voltage regulator, which is often part of the alternator. A quick charging-system test will show the voltage.
How much does it cost to fix a P0563?
Testing is cheap or free. Replacing the alternator runs about $150–450 installed.
Related codes
P0562
P0562 Code: System Voltage Low
P0560P0560 Code: System Voltage Malfunction
P0620P0620 Code: Generator Control Circuit Malfunction
Updated 2026-08. This page is informational and not a substitute for professional diagnosis.